Rotary electric switch.



PATENTED JAN. 9, 1906.

J. DUGDILL. ROTARY ELECTRIC SWITCH.-

APPLIOATION FILED MAR.15, 1905.

3 SHEETS-SHEET 1.

PATENTBD JAN. 9, 1906.

J. DUGDILL. ROTARY ELECTRIC SWITCH.

APPLICATION FILED MAR.15, 1906.

3 SHEETS-SHEET 2.

N0. 809,433. PATENTED JAN. 9, 1906.

J. DUGDILL.

ROTARY ELEGTRIG SWITCH.

APPLIGATION FILED MAR.15, 1905.

- 3 SHEETS-SHEET 3.

INVENTOR- for suspended incandescent electric lamps,

UNITED STATES PATENT OFFICE.

I JOHN DUGDILL, OF FAILSWORTH, MANCHESTER, ENGLAND.

ROTARY ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Jan. 9, 1906.

To all whom it may concern:

Be it known that I, JOHN DUGDILL, electrical engineer, a subject of the King of Great Britain, residing at 305 Oldham road, Fails worth, Manchester, in the county of Lancaster, England, have invented new and useful Improvements in Rotary Electric Switches, of which the following is a specification.

My invention has reference to a rotary switch for electrical conductors which is applicable as a combined ceiling rose and switch but may also be used as a switch for other electric-current-consuming apparatus.

The essential novel features of my invention consist in the provision of a rotary drum carrying one or more metallic brushes or other conductors. Opposite the ends of the drum are arranged fixed contact-plates connected to the positive and negative terminals of the permanent wires of the circuit. In conjunction with such a system of conductors I employ a shield of insulating material. A coiled spring is attached to the drum and to a fixed axis, the spring being preferably arranged within the interior of the drum. Flexible insulated conducting-wires are connected to the brushes or conductors on the drum and are wound upon the drum. When the flexible wires are pulled down to uncoil them from the drum, the spring is further wound up, owing to the rotation of the drum, and when the flexiblewires are released the spring serves to rotate the drum in a contrary direction to wind on the wires. The brushes and non-conducting shields and the fixed contact-plates are so arranged and shaped that when the flexible conductors are pulled down the drum is rotated to bring its brushes into either continuous or periodic contact with the fixed contact-plates, the current being then on, and this is maintained throughout all the period of rotation of the drum in this direction and also while the drum is at rest. Immediately, however, the rotation of the drum is reversed the non-conducting shield is interposed between the rotary and fixed conductors, the current being then off and remaining off in any position of the drum until its direction of rotation is again reversed by the flexible insulated wires being pulled down, and in order that my inventionmay be fully understood I will proceed to describe the same with reference to the accompanying drawings, in which- Figure 1 shows my improved switch in outi side elevation in conjunction with a hanging incandescent lamp. Fig. 2 is a plan of the switch. Fig. 3 is a sectional plan showing the drum with its attached brushes or conductors, the non-conducting shields being removed. Fig. 4 is a similar view with the drum in section and turned a quarter-revolution to show more clearly the brushes and shields. Fig. 5 is a sectional elevation to illustrate an end view of the drum and the shield. Fig. 6 is a similar view with the drum removed, showing a face view of one of the fixed contact-plates connected to one of the terminal blocks of the permanent wiring. Fig. 7 is a detached face view of one of the fixed contact-plates on a larger scale. Fig. 8 is an edge View thereof. Fig. 9 is a still further enlarged plan view, parts of which are broken away for want of space, partly in section, showing how in one direction of rotation of the drum the brushes make contact with the fixed contact-plates and on the reverse rotation how the non-conducting shields are interposed between the brushes and the fixed contactplates. Fig. 10 shows a modification in which the contact-plates are revoluble and the conductors and the non conducting shields are fixed. Fig. 11 is a diagram showing how the contact-plates may be provided on one side with insulated faces. Fig. 12 is a diagram indicating how periodic contact may be made.

The chamber a of the switch is of porcelain or any other suitable material and formed with screw-holes 1", whereby the switch can be secured in any desired position. Within the body a are arranged the terminal blocks 1), provided for connecting to the permanent wiring of an installation, to which blocks are connected the contact -plates 0, as clearly shown in the enlarged plan view of Fig. 9. The contact-plates have a bar 8, by means of which they are connected to the terminal blocks 5, and the whole is held to the chamber a by screws t. These contact-plates c are formed from a disk of copper or other conductor of electricity and are cut in three places 1, 2, and 3. The number of such cuts may be varied. Parts of the disk are cut away at the slots 1, 2, and 3, and the edges of the disks between the cuts are bent to an angle, one end inward and the other outward, as clearly seen in the plan views Figs. 8 and 9. The exact construction and shape of the contact-plates may be varied. A spindle d, normally fixed, but rotatable by means of a slot formed in the head, is mounted in bearings in the chamber a of the switch, and upon this spindle is loosely mounted a hollow drum e, of porcelain or other material, within the interior of which is coiled a springf, secured at one end to the drum and at the other end to a pin g on the spindle d. On rotating the spindle d by means of a screw-driver the spring can be put under the requisite tension. 7 A suitable pawl h, carried by the switch-body, engaging with a ratchet-head i on the rotatable spindle d, locks the spindle when the spring has been wound up. On each side of the drum 6 is mounted a brush or conductorj and above these a shield 7c, of non-conducting material, arranged to overlap the brush j, as shown in Fig. 4. The approximate shape of the conductor 3' and shield 7c is indicated in sectional plan in Fig. 9. Flexible insulated conductors or wires m are connected to terminals n of the brushes y', as shown in the plan View Fig. 3, and the flexible conductors are wound upon the drum 6 and connected to the lamp n or other electrical apparatus. To relieve the strain on the terminals n when the insulated wires m are pulled down to rotate the drum, the wires after leaving the terminals n are threaded through two holes 0 0 in the flanges of the drum 6, (see Fig. 5,) which serve to grip the wires and cut off all strain beyond this point upon the terminals a.

The action of the switch will be more clearly seen from an inspection of Fig. 9. When the insulated wires m are pulled down, the drum 6 is rotated in the direction of the arrow marked 1). It will be seen that this movement directs the brushes j in contact with the front faces of the contact-plates c, the shields k, of non-conducting material, rotating at the back of the contact-plates and serving to deflect the flexible angularly-bent portion of the contact-plates c inward in contact with the brushes The brushes are thus in contact with the plates 0 not only when the drum is rotated by the downward pull of the flexible insulated wires m, but when the drum is brought to rest and the current to the lamp is thus on. When it is desired to switch off the current, the insulated wires m are lifted to take off the weight of the lamp, which serves as a counterbalance to the coiled springf, the spring then acting to reverse the direction of rotation of the drum 0 and coil the insulated wires thereon. It will be seen that this reverse rotation in the direction of the arrow 9 at once and constantly during the rotation of the .drum in this direction interposes the overlapping shield 7c of non-conducting material between the brushes j and the fixed contact plates 0, so that until the lamp is again pulled down the current is off.

I do not confine myself to the exact arrangementshown, as the details may be varied without departing from the spirit of my invention. For instance, it is not necessary that contact should be made and broken at both sides of the drum 6, as at one side continuous contact with one of the terminals of the permanent wiring may be maintained. I might also arrange that the contact-plates 0 should be carried by and rotated with the drum c'and be connected to the terminals n of the lamp or other electrical apparatus. In this case the brushes would be connected to the terminals of the permanent wiring and, together with the shields 76, be mounted as fixtures on the body a of the switch, as illustrated in Fig. 10. The revolving shield 7c may be dispensed with, and one face of the contact -plate 0 may be coated or covered with ebonite or other suitable insulating material c, as illustrated in the diagram Fig. 11. Thus contact will be made and broken according to the direction of revolution of the drum 0. Instead of rotating the drum by pulling on the insulated wires m I may provide an independent cord for this purpose.

I do not claim as a novel feature per se the use of a spring-drum in conjunction with insulated wires m conducting current to the lamp, as I am aware this has been previously used to facilitate the raising and lowering of the lamp.

In the foregoing description and drawings contact has been continuously made on pulling down the lamp, as the brush or collector has made contact with the neighboring portion of the slotted contact-plate 0 before leaving the previous portion. It is evident, however, that periodic or intermittent contact.

could be made by increasing the gap between neighboring portions of the contact-plate c and reducing the length of the brush or collector 1'. This is indicated in diagram in Fig. 12.- It will be seen from this diagram that the collector y' will be entirely removed from .drum, a support for the same, contacts on each of said parts and means for permitting said contacts to engage each other when the drum rotates in one direction and for preventing engagement when the drum rotates in the other direction, substantially as described.

2. A rotary switch comprising a springdrum, a support therefor, a contact on each of said parts, and a shield of non-conducting material carried by said drum said shield covering the contact on the drum and being set at an incline to said drum so that when the drum is rotated in one direction said shield will engage with a contact on the support and force said contact into engagement with the drum-contact, while when the drum is rotated in the opposite direction said shield will prevent engagement of the contacts, substantially as described.

3. A rotary switch consisting of a body of non conducting material, a spring drum mounted to rotate therein, a current-consuming apparatus, Wires connecting said apparalo the drum in one direction and for preventing the engagement of said plates on the rotation of the drum in the other direction, substan tially as described.

In testimony whereof I have signed my name to this specification in the presence of 15 tWo subscribing Witnesses.

JOHN DUGDILL. Witnesses:

JOSHUA ENTWIsLE, ALFRED YATES. 

